What was done
Circular FACE plots (30-m diameter) receiving 350 and 560 ppm CO2 were established in 1996 on a 14-year-old loblolly pine (Pinus taeda L.) plantation in North Carolina, USA, to determine the effects of elevated CO2 on this economically important timber species commonly grown in the southeastern USA.  In this particular paper, the authors collected seeds from trees exposed to both atmospheric CO2 concentrations to study the effects of elevated CO2 on seed characteristics, germination success and early seedling growth.  Thus, seeds were collected from both ambient and elevated atmospheric CO2 environments, characterized, and germinated under the same and reciprocal atmospheric CO2 concentrations.

What was learned
Seeds collected from CO2-enriched trees were 91% heavier than those collected from trees growing in ambient air.  In addition, the CO2-enriched seeds had a lipid content that was 265% greater than that observed in seeds produced on the ambient-treatment trees.  Germination success for seeds developed under atmospheric CO2 enrichment was more than three times greater than that observed for control seeds developed at ambient CO2, regardless of germination CO2 concentration.  Moreover, the seeds from the CO2-enriched trees germinated approximately five days earlier than their ambiently-produced counterparts, again, regardless of germination CO2 concentration.  Seedlings developing from seeds collected from CO2-enriched trees displayed significantly greater root lengths and needle numbers than seedlings developing from trees exposed to ambient air, also regardless of current growth CO2 concentration.

What it means
As the CO2 content of the air continues to increase, loblolly pine trees will likely display significant increases in their photosynthetic rates.  Enhanced carbohydrate supplies, resulting from this phenomenon, will likely be used to increase seed weight and lipid content.  Such seeds should consequently exhibit significant increases in germination success, and their enhanced lipid content will likely lead to greater root lengths and needle numbers in developing seedlings.  Thus, when these seedlings become photosynthetically-active, they will likely photosynthesize and produce biomass at greater rates than those currently exhibited by seedlings growing under ambient CO2 concentrations.